10 



instructive; they are within reach at all times, found as they are 

 almost everywhere, easily cultivated in the aquaria, and can readily 

 be examined in the living condition. Their relative simplicity of 

 structure, their delicate arrangement of parts, exquisite beauty of 

 colour, and the interesting life histories which belong to so many 

 of them, all combine to make this group of plants a truly fascinating 

 field of study. The WTiter then proceeded to describe .several forms 

 of algffi, beginning with the simple unicellular chlamydococcus, 

 and pointing to this as the starting point in the evolution of the 

 spherical colonial form, as found in pandorina moruni, eudorina 

 and volvox globator. Next showing how a similar miscellular 

 organism like chlamydococcus would likely become the attached 

 cell and develop the filamentous algje like ulothrix zonata, 

 oedogonium and bulbochoete. Passing from the.se, some of the 

 more interesting branching forms were next considered, such as 

 choetophora pisiforms and elegans, batrachospnrmum and draper- 

 naldia, and finally nostoc sphoericum and hydrodictyon utriculatum. 

 The paper was illustrated wiih lantern transparencies shown by the 

 oxy -hydrogen light. 



At tlie Conversazione the following .subjects were illusti'ated : — 



^Bulbochneta W. H. Read. 



Cylindrosperraum macrospermum Jo.seph Gould. 



Cladophora crLspata G. Watson Gray. 



Chretophora elegans Alfred Leice.ster. 



Do. A. T. Smith, Jun. 



Do. pi.siformis Rev. Frank Ballard, M. A. 



Drajiarnaldia glomerata J. Haerord Levvi.s. 



Do A. Norman Tate. 



Euglena and Protococcus Henry Kendall, B.A. 



Fresh "Water Algae in congugation T. Musk ett. 



No.stoc sphcericum J. Montgomery, Jun. 



Do. and Hydrodictyon utriculatum. William Narramork. 



Oscillaria tenuis F. C. Larkin, M.R.C.S. 



Polypothrix coactilis Alfred Johnson. 



Spirogyra nitida (congugation) Edward Newall. 



> Ulothrix zonata (zoospores) Frank B. Allen. 



Ceramium ciliatum J. M. William s. 



Fiicus vesiculosus, transverse section of Thallus R. Nicholson. 



Larva of Dytiseus margiualis T. Oliver. 



